Audi Workshop Service and Repair Manuals

Removing and installing control unit and hydraulic unit (2.0 ltr. TDI) Vehicles without diesel particulate filter   Note t  From model year 2009 onwards, sensor unit -G419- is installed in ABS control unit (with ESP) -J104-. t  From model year 2009 onwards, ABS control unit (with ESP) -J104- must be renewed if sensor unit -G419- is defective. t  From model year 2009 onwards, ABS control unit (with ESP) -J104- must be calibrated after it has been renewed. t  From model year 2009 onwards, steering angle and brake pressure are also measured by the ABS control unit (with ESP) -J104-; these values must then be calibrated. On vehicles with Mark 60EC system If the ABS control unit -J104- is renewed on vehicles with Mark 60EC system, an additional basic setting must be performed for the inlet valves and separating valves → Chapter. To do so, use the vehicle diagnosis, testing and information system -VAS 5051 x - or -VAS 5052-.

Special tools and workshop equipment required

t	Torque wrench -V.A.G 1331-

t	Torque wrench -V.A.G 1410-

t	Brake pedal actuator -V.A.G 1869/2-

Sealing plug repair kit, Part no. 1H0 698 311 A After separating the control unit from the hydraulic unit, you must fit the transport protection for contact pins onto the hydraulic unit. No warranty can be assumed for hydraulic units without transport protection. 1 -  Transport protection for contact pins (foam) 2 -  Sealing plugs M10 for brake lines and tapped holes 3 -  Sealing plugs M12 for brake lines and tapped holes Removing

–  Insert brake pedal actuator -V.A.G 1869/2- between brake pedal and driver's seat. Depress the brake pedal at least 60 mm. –  Connect hose of bleeder bottle to bleeder screws of front left and rear left brake calipers and open bleeder screws.   Note This will release the pressure in the hydraulic unit. –  Close front left and rear left bleeder screws. –  Do not remove brake pedal actuator -V.A.G 1869/2-.

–  Remove engine cover panel -1 and 2-. –  Unfasten and push aside turbocharger air duct.

–  Release connector at control unit -arrow 1- and unplug -arrow 2-.   Note t  Make sure brake fluid does not get into connector housing of control unit. This can result in corrosion of the contacts and failure of the system. t  Use compressed air to carefully clean connector housing if necessary.

–  As protection against escaping brake fluid, place a sufficient number of lint-free cloths in area beneath control unit and hydraulic unit. –  Mark brake lines.

–  Unscrew brake lines from hydraulic unit -1- to brake master cylinder and tie in place. –  Disconnect remaining brake lines -2- on hydraulic unit.   WARNING Do not bend the brake lines in the vicinity of the hydraulic unit. –  Seal brake lines and tapped holes with sealing plugs from repair kit.

–  Pry the hydraulic unit with control unit upwards, see -arrow-.

–  Unscrew bolts on bracket for hydraulic unit -1- (tightening torque 8 Nm). Removing control unit from hydraulic unit –  Place hydraulic unit on a clean flat surface with control unit facing downwards.

–  Unscrew Torx socket head bolts -arrows- from hydraulic pump.   WARNING Hydraulic pump must not be separated from hydraulic unit.

–  The hydraulic pump must therefore be secured on the hydraulic unit with the red retainer -1- from the repair kit and two sealing plugs -2-.

–  Carefully lift hydraulic unit with hydraulic pump off control unit at seam -1-.

When pulling off the control unit, ensure that the hydraulic unit contact pins are not canted against the control unit solenoids. Item 2 Adapter for pump motor –  Cover control unit solenoids with a lint-free cloth. After disconnecting control unit and hydraulic unit, fit transportation protection for contact pins. Installing new control unit   WARNING Severe shocks or jolts can damage the control unit. The control unit must not be re-installed if it has been damaged in any way. t  First clip in the adapter for pump motor until it engages with a click before installing the new control unit. Make sure not to damage the adapter guide. t  The adapter (supplied as replacement part for control unit) can only be clipped in once and then no longer detached. t  The white paste on the bottom of the control unit serves as sealant and must not be removed. t  To ensure that the components are kept clean and to prevent damage, do not touch any contact surfaces on the adapter, pressure sensor or control unit, or the silicone gel and sealing components by hand or with tools, etc. –  Clip adapter into adapter guide until it engages with a click. –  Place control unit on hydraulic unit (make sure not to cant control unit). –  Bolt control unit to hydraulic unit with the new Torx socket head bolts supplied.   Note t  To avoid any risk of leakage at the flexible seal, a new control unit must not be fitted more than twice onto an "old" hydraulic unit that is being re-installed. t  A control unit which has been in operation while the vehicle is being driven must not be fitted a second time.

–  Unscrew cross-head screw -1-. –  Unclip line -2-.

–  Unscrew hexagon nut -1- (tightening torque 20 Nm). Installing Installation is performed in reverse sequence; note the following:   Note t  Do not remove sealing plugs from new hydraulic unit until corresponding brake line is ready to be fitted. t  If sealing plugs are removed from hydraulic unit sooner, brake fluid may escape and it may no longer be possible to fill and bleed the unit properly. –  When assembling control unit and hydraulic unit, make sure contact pins of hydraulic unit do not cant on control unit solenoids. –  Connect lines in accordance with markings → Chapter. –  Secure ABS unit to bracket.   Note Do not tighten bolts completely. This will make it easier to attach the individual brake lines to the hydraulic unit. –  Tighten all brake line connections. –  After tightening brake lines, tighten hydraulic unit. –  Insert and bolt on turbocharger air duct.

–  Install engine cover panel -1 and 2-. –  Bleed brake system → Chapter. –  If a new control unit has been fitted, it must be encoded. To do so, use the vehicle diagnosis, testing and information system -VAS 5051 x - or -VAS 5052-. –  Connect vehicle diagnosis, testing and information system and select „function/component“ for function test → Chapter. Then –  „Running gear“ –  „Brake system“ –  „01 - Self-diagnosis compatible systems“ –  „J104 - Control unit for ABS/TCS/ESP Mark 60“ –  „J104 - Control unit for ABS/TCS/ESP, Functions“ –  „J104 - Encoding control unit“ –  Perform final control diagnosis after attaching brake lines to hydraulic unit. Vehicle diagnosis, testing and information system -VAS 5051 x - or -VAS 5052-   Note t  If the ABS control unit (with ESP) -J104- is renewed, the following senders must be calibrated: t  Steering angle sender -G85- t  Lateral acceleration sender -G200- t  Brake pressure sender 1 -G201- t  Longitudinal acceleration sender -G251- (only four-wheel drive vehicles) t  From model year 2009 onwards, steering angle and brake pressure are also measured by the ABS control unit (with ESP) -J104-; these values must then be calibrated. t  ESP road test and system test must then be carried out. To do so, use the vehicle diagnosis, testing and information system -VAS 5051 x - or -VAS 5052-. –  Connect -VAS 5051 x - or -VAS 5052- and select „function/component“ for function test → Chapter. –  „Running gear“ –  „Brake system“ –  „01 - Self-diagnosis compatible systems“ –  „J104 - Control unit for ABS/TCS/ESP Mark 60“ –  „J104 - Control unit for ABS/TCS/ESP, Functions“ On vehicles with Mark 60EC system If the ABS control unit -J104- is renewed on vehicles with Mark 60EC system, an additional basic setting must be performed for the inlet valves and separating valves → Chapter. To do so, use the vehicle diagnosis, testing and information system -VAS 5051 x - or -VAS 5052-.   Note Final control diagnosis can be used to establish whether line connections have been interchanged. Tightening torques

Component		Nm
Control unit to hydraulic unit		4
Hydraulic unit to bracket		8
Brake lines to hydraulic unit		14

Renew bolts